<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Filter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: PregReplace.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 *
 * @see Zend_Filter_Interface
 */
require_once 'Zend/Filter/Interface.php';

/**
 *
 * @category Zend
 * @package Zend_Filter
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Filter_PregReplace implements Zend_Filter_Interface {

    /**
     * Pattern to match
     * @var mixed
     */
    protected $_matchPattern = null;

    /**
     * Replacement pattern
     * @var mixed
     */
    protected $_replacement = '';

    /**
     * Is unicode enabled?
     * @var bool
     */
    protected static $_unicodeSupportEnabled = null;

    /**
     * Is Unicode Support Enabled Utility function
     * @return bool
     */
    static public function isUnicodeSupportEnabled () {
        if (self::$_unicodeSupportEnabled === null) {
            self::_determineUnicodeSupport ();
        }
        return self::$_unicodeSupportEnabled;
    }

    /**
     * Method to cache the regex needed to determine if unicode support is available
     * @return bool
     */
    static protected function _determineUnicodeSupport () {
        self::$_unicodeSupportEnabled = (@preg_match ('/\pL/u', 'a')) ? true : false;
    }

    /**
     * Constructor
     * Supported options are
     * 'match' => matching pattern
     * 'replace' => replace with this
     * @param string|array $options
     * @return void
     */
    public function __construct ($options = null) {
        if ($options instanceof Zend_Config) {
            $options = $options -> toArray ();
        } else 
            if ( ! is_array ($options)) {
                $options = func_get_args ();
                $temp = array();
                if ( ! empty ($options)) {
                    $temp['match'] = array_shift ($options);
                }
                if ( ! empty ($options)) {
                    $temp['replace'] = array_shift ($options);
                }
                $options = $temp;
            }
        if (array_key_exists ('match', $options)) {
            $this -> setMatchPattern ($options['match']);
        }
        if (array_key_exists ('replace', $options)) {
            $this -> setReplacement ($options['replace']);
        }
    }

    /**
     * Set the match pattern for the regex being called within filter()
     * @param mixed $match - same as the first argument of preg_replace
     * @return Zend_Filter_PregReplace
     */
    public function setMatchPattern ($match) {
        $this -> _matchPattern = $match;
        return $this;
    }

    /**
     * Get currently set match pattern
     * @return string
     */
    public function getMatchPattern () {
        return $this -> _matchPattern;
    }

    /**
     * Set the Replacement pattern/string for the preg_replace called in filter
     * @param mixed $replacement - same as the second argument of preg_replace
     * @return Zend_Filter_PregReplace
     */
    public function setReplacement ($replacement) {
        $this -> _replacement = $replacement;
        return $this;
    }

    /**
     * Get currently set replacement value
     * @return string
     */
    public function getReplacement () {
        return $this -> _replacement;
    }

    /**
     * Perform regexp replacement as filter
     * @param string $value
     * @return string
     */
    public function filter ($value) {
        if ($this -> _matchPattern == null) {
            require_once 'Zend/Filter/Exception.php';
            throw new Zend_Filter_Exception (get_class ($this) . ' does not have a valid MatchPattern set.');
        }
        return preg_replace ($this -> _matchPattern, $this -> _replacement, $value);
    }

}
